Environmental impact of transport
The health and environmental impact of transport is significant because transport burns most of the world's petroleum. This causes illness and deaths from air pollution, including nitrous oxides and particulates, and is a significant cause of climate change through emission of carbon dioxide. Within the transport sector, road transport is the largest contributor to climate change.
Environmental regulations in developed countries have reduced the individual vehicle's emission.However, this has been offset by an increase in the number of vehicles, and increased use of each vehicle (an effect known as the Jevons paradox).Some pathways to reduce the carbon emissions of road vehicles have been considerably studied.Energy use and emissions vary largely between modes, causing environmentalists to call for a transition from air and road to rail and human-powered transport, and increase transport electrification and energy efficiency.
Other environmental impacts of transport systems include traffic congestion and automobile-oriented urban sprawl, which can consume natural habitat and agricultural lands. By reducing transport emissions globally, it is predicted that there will be significant positive effects on Earth's air quality, acid rain, smog, and climate change. Health effects of transport include noise pollution and carbon monoxide emissions.
While electric cars are being built to cut down CO2 emission at the point of use, an approach that is becoming popular among cities worldwide is to prioritize public transport, bicycles, and pedestrian movement. Redirecting vehicle movement to create 20-minute neighbourhoods that promotes exercise while greatly reducing vehicle dependency and pollution. Some policies include levying a congestion charge on cars travelling within congested areas during rush hour.
Environmental impact of aviation[edit | edit source]
Aircraft engines produce gases, noise, and particulates from fossil fuel combustion, raising environmental concerns over their global effects and their effects on local air quality.Jet airliners contribute to climate change by emitting carbon dioxide (CO2), the best understood greenhouse gas, and, with less scientific understanding, nitrogen oxides, contrails and particulates.Their radiative forcing is estimated at 1.3–1.4 that of CO2 alone, excluding induced cirrus cloud with a very low level of scientific understanding.In 2018, global commercial operations generated 2.4% of all CO2 emissions.
Jet airliners have become 70% more fuel efficient between 1967 and 2007, and CO2 emissions per revenue ton-kilometer (RTK) in 2018 were 47% of those in 1990. In 2018, CO2 emissions averaged 88 grams of CO2 per revenue passenger per km.While the aviation industry is more fuel efficient, overall emissions have risen as the volume of air travel has increased. By 2020, aviation emissions were 70% higher than in 2005 and they could grow by 300% by 2050.
Aircraft noise pollution disrupts sleep, children's education and could increase cardiovascular risk.Airports can generate water pollution due to their extensive handling of jet fuel and deicing chemicals if not contained, contaminating nearby water bodies.Aviation activities emit ozone and ultrafine particles, both of which are health hazards. Piston engines used in general aviation burn Avgas, releasing toxic lead.
Aviation's environmental footprint can be reduced by better fuel economy in aircraft, or air traffic control and flight routes can be optimized to lower non-CO2 effects on climate from NO
x, particulates or contrails.Aviation biofuel, emissions trading and carbon offsetting, part of the ICAO's CORSIA, can lower CO2 emissions. Aviation usage can be lowered by short-haul flight bans, train connections, personal choices and aviation taxation and subsidies. Fuel-powered aircraft may be replaced by hybrid electric aircraft and electric aircraft or by hydrogen-powered aircraft.Since 2021, the IATA members plan net-zero carbon emissions by 2050, followed by the ICAO in 2022.
Effects of cars[edit | edit source]
The externalities of automobiles, similar to other economic externalities, represent the measurable costs imposed on those who do not own the vehicle, in contrast to the costs borne by the vehicle owner. These externalities include factors such as air pollution, noise, traffic congestion, and road maintenance costs, which affect the broader community and environment. Additionally, these externalities contribute to social injustice, as disadvantaged communities often bear a disproportionate share of these negative impacts.
According to Harvard University, the main externalities of driving are local and global pollution, oil dependence, traffic congestionand traffic collisions; while according to a meta-study conducted by the Delft University these externalities are congestion and scarcity costs, accident costs, air pollution costs, noise costs, climate change costs, costs for nature and landscape, costs for water pollution, costs for soil pollution and costs of energy dependency.
Environmental impact of shipping[edit | edit source]
The environmental impact of shipping include air pollution, water pollution, acoustic, and oil pollution. Ships are responsible for more than 18% of nitrogen oxides pollution, and 3% of greenhouse gas emissions.
Although ships are the most energy-efficient method to move a given mass of cargo a given distance, the sheer size of the industry means that it has a significant effect on the environment. The annual increasing amount of shipping overwhelms gains in efficiency, such as from slow-steaming. The growth in tonne-kilometers of sea shipment has averaged 4 percent yearly since the 1990s, and it has grown by a factor of 5 since the 1970s.
The fact that shipping enjoys substantial tax privileges has contributed to the growing emissions.